Combined boiler and water heater



June 19; 1934. KROGER 1,963,624

COMBINED BOILER AND WATER HEATER Filed Jan. 9, 1934 3 Sheets-Sheet l :llll' IH June 19, 1934. b 1,963,624

COMBINED BOILER AND WATER HEATER Filed Jan. 9, 1934 s Sheets-Sheet 2 June 19, 1934. R KROGER COMBINED BOILER AND WATER HEATER :5 Sheets-Sheet 3 Filed Jan. 9', 1934 In van for, Fur/06 7 Patented June 19, 1934 (UNITED STATES PATENT OFFICE Application January 9,

16 Claims.

My invention relates to a combined boiler and water heater designed for economical use with an automatically controlled supply of either oil or gas as the fuel, and constructed for simultaneously aifordinga supply of steam at low pressure and a separate supply of hot water.

Generally speaking, my invention has the following objects:

(1) Providing an oil-burning or gas-burning mi boiler which is of much smaller fuel consumption than the types heretofore commonly used for house-heating purposes, and'one which will generate a head of steam in a small fraction of the time required with the now customary fluid-burnf ing boilers.

(2) Providing a boiler for such purposes which will be unusually low in cost, small in size and weight, durable and safe, in comparison with the heretofore employed types.

water-evaporating surface of much greater area, in proportion to the water content of the boiler, than is found in the heretofore used boilers, thereby greatly reducing the water capacity jneeded in the boiler for any given steam-generating capacity.

(4) Enabling this relatively small water content to be employed while still complying with the insurance requirements for safety. 7 (5) Providing a combined (low-pressure steam) boiler and hot water heater suitable for household use and in which the water compartment consists of two easily assembled sections which together house the boiler.

(6) Constructing such a combined boiler and water heater so that the heat-receiving surfaces will all be exterior ones.

(7) Constructing the two-section water compartment so that it will support the boiler housed by it, without requiring the boiler to be fastened to either section.

(8) Providing a combined boiler and hot water heater which also can be economically operated (3) Constructing the boiler so as to present a 1934, Serial No. 705,905

plane in Fig. 6, of the two halves of the waterheating compartment, with portions of each half of the water compartment broken away.

Fig. 2 is a perspective view of one of the water compartments which jacket the steam-generating or boiler unit, with a portion broken away to show the combustion gas outlet leading to the flue, drawn on a smaller scale than Fig. 1.

Fig. 3 'is a similarly reduced perspective view of the upper portion of the water compartment shown in Fig. 2, including adjacent portions of ducts and other parts, and Fig. 4 is a perspective view of the lower portion of the same compartment. i

Fig. 5 is a. section through the upper portion of 7i) the assembled boiler and hot-water heater,-taken; along the line 5-5 of Fig. 3, showing the branch'. steam pipes used for heating water during the summer months.

Fig. 6is a fragmentary side elevation of the assembled heater, as viewed from the line 6-6 in Fig. 1, drawn on the same scale as Fig. 5 and including the water duct connecting .the lower portions of the two water compartments.

Fig. 7 is a reduced central vertical section8'0 through an oil-burning boiler and water heater embodying my invention; taken along the junc-. ture plane of the two water compartments as in Fig. 1.

In each of the illustrated embodiments my combined boiler and water heater comprises three main parts, the inner of which is an upright boiler designed for high efiiciency, small water capacity in proportion to the amount of steam which is to be generated per hour, and speedy generation of steam. The other two main parts are oppositely concaved water compartments, each generally of the form of a hollow half- "thirnble as shown in Fig. 2. These watercompartments jointly house and also support the in- 1181' or boiler unit and are heated conjointly with the said boiler unit, but have separate pipe con'v nections from those of the boiler unit.

The boiler 651 over one lateral half of the top of the upper gauge connected to this upper header.

the two boiler-jacketing water compartments, and the upper header has its cylindrical side wall 41) of considerably larger diameter than that of the lower header. Furthermore, I provide the upper header with nubs 33 projecting to an equal distance from its riser side lb to center the boiler within the water jacket as hereafter described.

The two headers are connected by upright riser pipes 6 closely adjacent to the periphery of the 'lower header, which pipes preferably have their axes in a common cylindrical surface, and these pipes are consecutively spaced from each other by a distance which is a small fraction of their diameter, namely only by a sulhcient distance to permit portions of the fiame and of the combustion gases to pass freely between them.

Depending from the bottom 4 of the upper header into the space surrounded by the rise pipes 6 are upwardly open water-storing drop tubes '7. All of these drop tubes present closed lower ends 7d at a uniform distance above the top of the burner 3, namely at a level near but above the midheight of the spacing between the bottom 21 of the lower header and the top 40. of the upper header, so that the lower ends of all of the drop tube will be above the reach of the burner flame to present a depositing of soot on these drop tubes. Moreover, these drop tubes preferably are symmetrically distributed with respect to the common upright axis of the two headers and are of as great a number (as shown in Fig. 3 by the header-bottom bores for these drop tubes) as can be freely disposed in the space surrounded by the upper portions of the riser tubes 6.

Leading to the lower header 1 is a filler pipe 8 through which water may be admitted (by opening a valve 9 connected to a water main) for filling the boiler to the desired level L in the upper header, which level the user can see from a water When my boiler is to be used in connection with steamheated hot-water radiators I also provide another water pipe 11 leading to the lower header, through which pipe the water of condensation from the steam in the radiators can be returned to the boiler. If not used for such a house heating system, this companion water pipe 11 may be omitted, or may be shut off by the valve 12 as shown in Fig. 1.

The water-heating boiler jacket This consists of two parts, separately manufactured from sheet iron and each of the general shape of one half of a hollow thimble, each half of which has a semi-cylindrical outer riser wall (14 or 15 in Fig. 6), a top 16 generally formed as a diametric half of a dome, and a horizontal bottom 17 of semi-annular shape. The inner wall of each jacket half comprises a half-tubular lower 'portion 18 of smaller diameter than the lower header 1, a main half-tubular portion 19 extending upwardly to a level somewhat above the top of the cylindrical riser side 41) of the upper header, and a generally half-dome shaped top 20 arching header. Connecting the upper end of the lower half-tubular inner wall 18 of each jacket half is a horizontal half-ring-shaped ledge 21 upon which the lower header 1 seats when my boiler and water heater is assembled, and two generally fiat and upright end plates 22 connect the free edges of the inner jacket wall with those of the outer jacket wall.

To afford passages for the various ducts associated with the boiler, the two end plates 22 are connected in the upper portion of each jacket half by a semi-tubular inner jacket wall part 23, so that these half-tubes 23 in the adjoined jacket halves will jointly form a bore through which the steam pipe extends. Then 1 likewise form an upright semi-tubular indentation 24 at each side of the said half-tube 23 in each jacket half, to afford passages in the assembled jacket halves for two riser pipes leading from the top of the upper header, one of these riser pipes (25) leads by means of which the pressure in this header may automatically control the supply of gas to the burner, the details of which are not illustrated since such control arrangements are well known in the art and form no part of my present invention; and the companion riser pipe 4:1 leads to a pressure gauge 42.

One flat end wall 22 of each jacket half is also formed (as in Fig. 2) with two horizontal semicylindrical indentations 26 to afford bosses in the jacket for water pipes 27 connected to the water gauge 10, and with two indentations 28 to afford passage ways for the water pipes 8 and 11 of Fig. 1. In addition, I mount a water outlet pipe 29 on the top of each jacket half, and also provide each jacket half with alined tubes 30 and 31 through which a branch steam pipe 32 may extend for the hereafter described purpose of heating water in that jacket during the warmer months of the year.

Installation To install my combined boiler and water heater, the needed horizontal main steam pipe 33 desirably is first rigidly positioned at greater elevation than the height of the two-part water jacket, with an upright steam pipe 5 depending from this main steam pipe.

The assembled boiler, with the burner 3 already disposed above the lower header and connected to an upright gas pipe 2, is next disposed under the upright steam pipe 5, and this boiler and burner unit is rotated so as to screw the top 4a of the header upon the threaded lower end of that pipe until the bottom 21 of the lower header is at a greater elevation from the floor F than the height of the lower bore wall portion 18 of the water jacket.

A sheet metal floor plate 34 is then slid under the jacket and propped up by suitable wedges to leave space between it and the floor F, after which the two jacket-halves are slid toward each other upon this plate, until the generally flat end walls 22 of one jacket-half contact with those of the other jacket-half. These two jacket halves are then clamped to each other by vertically spaced bands 35 (Figs. 1 and 5), thereby disposing the half-ring shaped ledges 21 on the two jacket halves under the lower header, and the lower portions of these jacket halves are connected by the piping 52 of Fig. 6 to water filler inlet pipe 53. During this jacket assembling, lateral nubs 38 on the upper header insure a proper centering of the jacket with respect to the header, so that the bore of the jacket will be coaxial with the boiler, thereby spacing the riser tubes 6 equally from the main bore portion 19 of both halves of the water jacket.

Next, the boiler unit is rotated (in a direction tending to unscrew its upper header from 1 the upright steam pipe 5) until the bottom of the lower header 1 seats on the ledges, the boiler being reached for this purpose through a bottom recess or doorway 36 which was formed in one of jacket halves as shown in Fig. 2. The

gas supply pipe is next inserted through the samerecess to attach it to the lower end of the gas pipe 2-, and a basal filling, 3.7 of concrete orthe like is rammed between the metal, base plate 34 and the floor so as to secure a firm engagement between the bottom header and the said ledges 21.

The exterior of the water jacket then desirably is coated with a, covering 39 ofheat-insulating material so as to reduce heat losses to the surrounding air and also toseal the juncture of. the two parts of the water jacket and to seal around, the ducts, such a covering being merely indicated by a dash-dotted. line 39 in-Fig. 7 since J it forms no part of my invention.

With the boiler of my heating appliance thus constructed, the tall rise tubes 6' effectively form. a vertically slitted wall which prevents an unduly rapid issuingof the flame and the combustion gases to the annular space between this circle of tubes and the adjacent bore wall portion 19.

Moreover, by making the upper header of.

larger diameter than the lower header, I considerably reduce thev width of the annular space S between the riser 'wall of the upper header and the main cylindrical bore portion 19 of the water jacket, in proportion to the minimum radial.

width S between the. upper part of the same bore portion and the riser tubes 6. This proportioning in itself delays. the upward flow of combustion gases alongside the upper header, and.

so does my making the space S between the upwardly tapering portion ofthe upper header top 4a and the tapering jacket bore portion 20 also of'a width considerably smaller than the said width S ,v namely less than half the latter width, as shown in Fig. 1. I

Consequently, the retarded flow of the combustion gases around and over the header to the flue 44 (shown in dotted lines in Fig. 1) decidedly reduces the heat losses up the flue. Moreover, when using gas as the fuel,I also provide the upper header with a tubular baffle 54 depending from its periphery and freely spaced both from the outer riser tubes 6 and the said jacket bore wall portion 19. This bafile desirably depends at least as far as the lower ends of the drop tubes'7, and preferably somewhat lower (as shown in Fig. 1) so that the hottest parts of the combustion gasesnamel'y those directly over the upwardly directed flames-wi1l be compelled to follow a tortuous path asshown by the dotted arrow line 46,'although relatively small portions of the fiame may issue along lines such as 47 to enhance the draft. 7

In addition to thus effecting a prolonged retention of heat under and adjacent to the upper header and the drop tubes, my design of boiler also presents an exceedingly large water surface area at the level L of the water in the upper header, and the exposing of both the sides and the bottoms of the drop tubes to the most intense heat of the flame expedites the vaporizing. of the water. Moreover, by using drop tubes. depending to an equal extentv from the upper header, I efiectively increase the water capacity of the header so that safety would only require the level L of the water (which level, can readily be maintained by suitably adjusting the, valve 9 inproportion to the desired rate of steam production) to be one inchv above'the bottom of the upper header. However, I desirably maintain this level at about two inches above the said header bottom, or at double the water depth above the bottom of the upper header which safety demands, so as to reduce the need of watching the water gauge.

With this depth of water in the upper header and with a header 14 inches in diameter in a boiler proportioned as in Fig. l, I have found such a boiler to generate steam within a half minute after the burner is lit and to show steam pressure on they steam gauge within a few minutes, and alsov have found that a six pound pressure can be raised inapproximately five minutes after starting.

Owing to this speedy steaming action andthe above described effective utilizing of the heat, I have also found that my boiler requires only about. a quarter as large a total water content as the ordinary types of boilers designed for house heating purposes, and that the above mentioned size (with the upper header 14 inches in diameter) will suffice for athousand square feet of steam radiation. However, the steam capacity can, readily be doubled by raising the depth of the water in the upper header another inch and correspondingly increasing the rate of gas consumpton.

Since the generally dome-like upper portion of the bore of the two-part water jacket presents a considerable surface area to the combustion gases, the water in the upper portion of this water jacket is heated much more speedily and intensively than that in lower portions of each half of the jacket. Consequently, this part of my appliance will readily furnish the needed hot water long before the lower water portions are adequately heated, and with only a small fraction of the heat-consumption which would be required if the entirebody of water in the water jacket had to be heated to tu-re;

The two water outlet pipes 29 leading upward from the two jacket halves are desirably conthe desired consumption temperanected'by a cross-pipe 60 to a hot-water consumption pipe 61 as shown in Fig. 6, and to use my combined boiler and water heater effectively also during the summer months when no steam is needed, I also provide the auxiliary provisions shown in Fig. 5, namely two branch steam pipes L.

32' leading from the steam pipe 5 and each extending through the upper portion of one water jacket half.

Each of these branch pipes 32 has an air-vent valve 48 con nected to its outer end and is sepa- J slopes upwardly away from the steam ppe 5 so 1 that any steam condensed in it. will flow into the upper header. When the valves controlled by the handles 49 are bothopen andthe valves 51 of Fig. l are closed, the branch steam pipes 32 heat the water in: each jacket half at a level close to i thatoi the corresponding hot-water outlet pipe 29, so that a low head of steam and a low fuel consumption suflices for supplying the hot water needed in the warmer months.

. 'When gas is used. as the fuel, the bottom recess 36 in one half of the water jacket is closed by a pair of doors 63, each of which doors is fitted with an adjustable damper 50 by means of which the supply of air can be regulated according to the chimney draft and the barometer. Such dampers are not needed with oil as the fuel, but the doors always are provided so as to afford access to the interior of the water compartment and to the burner.

When my appliance is to be used with oil, I preferably use an oil burner 57 (shown only exteriorly in Fig. 7) fitted into the upwardly directed end of the pipe through which the mixture of oil and air is blown, and for this purpose use a burner which will direct the flame generally upward or directly toward the bottoms of the pocket tubes 7. Since such a flame will be considerably taller than that of a gas burner, I correspondingly increase the length of the riser tubes 5 (as also shown in Fig. 7 in comparison with Fig. l) and I omit the tubular baffle 54 of Fig. 1 as well, as the air inlets and the inlet-controlling dampers 50 of Fig. 1, but otherwise can employ the same features as previously described in connection with Figs. 1 to 6.

With each of the two embodiments respectively shown in Fig. 1 and in Fig. '7, it will be obvious that I only boil water in the upper header and do not require the water in either the riser tubes 5 or the lower header 1 to be brought to the boiling point, and that the evaporation surface area (at the level L) is unusually large in proportion to the water content of the boiler. Consequently I avoid the need of intensely heating an excessively large amount of water in addition to that actually converted into steam, thus enabling me to employ a much smaller and cheaper boiler for obtaining a given steam-generating capacity, in comparison with the now customary types of boilers as designed for house-heating purposes and for use with either oil or gas as the fuel.

Moreover, by designing my appliance so that the boiler unit and each of the two water-jacket halves can be separately manufactured, and thereafter speedily assembled in the previously described manner, I secure the important advan tage that all of these parts can readily be passed through a doorway which is only slightly wider than the exterior radius of the water jacket. With all of the previous constructions of Waterjacketed boilers known to me, the water jacket could not be taken through an ordinary household doorway and therefore had to be assembled on the spot if it was to be installed in a building in which the basement was already finished, thereby decidedly increasing the cost of assembling the water jacket.

With the water jacket constructed in two halves as here shown, each jacket half can be completed in the factory where welding facilities and other equipment as well as ample working space are available and where the assembling can be duly inspected. Consequently I eliminate the need of sending trained men to each job for that purpose, in addition to reducing both the manufacturing and installation costs and can speedily have my appliance installed in an al ready completed building.

However, while I have heretofore described my invention in connection with drawings which include many desirable detail features of construction and arrangement, I do not wish to be limited in these respects, since many changes might be made without departing either from-the spirit of my invention or from the appended claims. Nor do I wish to be limited to the conjoint use of the various novel features of my here presented invention.

I claim as my invention:

1. A combined boiler and water heater, comprising an upright boiler of generally cylindrical contour, a fluid burner associated with the lower axial portion of the boiler, and a water heater housing the boiler; the water heater comprising two opposed water containers secured to each other, each water container being of the general shape of one diametric half of a thimble having two spaced riser walls connected to each other at both the top and the bottom, and having each end face thereof facing and sealed to the corresponding end face of the other water container.

2. A combined boiler and water heater as per claim 1, in which the two water containers are forrtned to afford ledges upon which the boiler sea s.

3. A combined boiler and water heater as per claim 1, including vertically spaced bands extending around the exterior of both water containers for clamping the two containers to each other.

l. A combined boiler and water heater as per claim 1, in which the two water containers are formed to afford ledges upon which the boiler seats, and in which the upper portion of the boiler has radially projecting lugs disposed for engaging the inner riser wall of one of the water contamer to center the said upper boiler portion with respect to the bore of the water heater.

5. A combined boiler and water heater as per claim 1, in which the boiler includes an upper header, a lower header, and. a plurality of riser tubes connecting the two headers and having the axes of the said tubes in a common upright cylindrical surface; the said tubes being spaced from the bore of the water heater by a sufficient distance to permit portions of the flame of the burner to move freely between the said tubes and the said bore.

6. A combined boiler and water heater as per claim 1, including a hot water outlet connected to the upper portion of each water container, a cold water inlet pipe connected to the lower portion of each water container, and a waterequalizing pipe connecting the lower portions of the two water containers.

'7. A combined boiler and Water heater as per claim 1, in which the generally thimble-shaped casing has an upright bore through its top, each water container having the inner wall of its upper portion formed to afford a diametric half of the said bore; and in which the boiler includes a steam pipe extending upwardly from the upper header of the boiler through the said upright bore and sealed to the upper portion of both Water containers.

8. A combined boiler and water heater, comprising a two-part generally thimble-shaped and hollow water container, and an upright boiler housed by the said water container; the generally thimble-shaped water container having an upright bore through its top, and the boiler including a steam pipe extending upwardly from the upper header between the upper portions of the two water containers; the combined boiler and water heater also including two steam ducts extending from the steam pipe respectively into the upper portions of the two water containers and each normally closed at its outer end, and two valves operable from the exterior of the said water containers for respectively controlling the said steam coils.

9. A combined boiler and water heater as per claim 8, in which each of the said steam ducts slopes upwardly away from the said steam pipe at a minor acute angle to the horizontal.

10. A combined boiler and water heater as per claim 1, in which the boiler includes an upper header, 2. lower header, and a plurality of riser tubes connecting the two headers and having the axes of the said tubes in a common up-.

right cylindrical surface; the said tubes being spaced from the bore of the water heater by a sufficient distance to permit portions of the flame of the burner to move freely between the said tubes and the said bore; and in which the upper header of the boiler is spaced from the said bore of the water heater, radially of the boiler, by a minor fraction of the aforesaid distance so as to reduce the velocity at which combustion gases move between the upper header and the said bore.

11. A completely encased boiler for use with fluid fuel, comprising an upright boiler including an upper header, a lower header, a plurality of raised tubes connecting the two headers and having the axes of the said tubes disposed in a common upright cylindrical surface, and a plurality of freely spaced drop tubes depending from the upper header in the space surrounded by the said riser tubes, the said drop tubes having closed lower ends disposed at a common elevation nearer to the upper header than to the lower header and beyond the direct reach of flame from the burner, and a Water-heating container housing the said boiler and having the major portion of its bore cylindrical and uniformly spaced from the said riser tubes.

12. A combined boiler and water heater installation comprising a two-part hollow thimbleshaped water container having an upright bore in its top and having an interior ledge intermediate its height; a stationary steam pipe extending downwardly through the said bore; and an upright boiler housed conjointly by the two parts of the water container and seated on the ledges of both of the said parts; the boiler having its upper portion threadedly connected to the said steam pipe, so that the boiler may be supported from the said pipe with its ledge-engaging portions at greater elevation than the said ledges, during the installation of the combined boiler and water heater.

13. In combination, a boiler comprising an annular lower header, an upper header, and a plurality of riser tubes connecting portions of the two headers near. the peripheries of these headers, all of the riser tubes having their axes disposed in a common cylindrical surface; and a generally thimble-shaped casing housing the said boiler and freely spaced both laterally and upwardly from all portions of the boiler, the

said casing having an interior ledge'intermediate of its height on which the lower header of the upper header affords an enlarged spacing from I the said lower interior face of the top of the casing to facilitate the flow of combustion gases to the said outlet.

15. A combined boiler and water heater as per claim 1, in which the boiler includes an upper header, a lower header, and a plurality of riser tubes connecting the two headers and having the axes of the said tubes in a common upright cylindrical surface; the said tubes being spaced from the bore of the water heater by a sufficient distance to permit portions of the flame of the burner to move freely between the said tubes and the said bore; and in which the upper header of the boiler is spaced from the said bore of the water heater, radially of the boiler,'by a minor fraction of the aforesaid distance so as to reduce the velocity at which combustion gases move between the upper header and the said bore; and a tubular bafile depending from the upper header substantially flush with the periphery of that header, the bafile presenting its lower end above the midheight of the vertical spacing between the two headers.

16. A combined boiler and water heater as per claim 1, in which the boiler includes an upper header, a lower header, and a plurality of riser tubes connecting the two headers and having the axes of the saidv tubes in a common upright cylindrical surface; the said tubes being spaced from the bore of the water heater by a sufiicient distance to permit portions of the flame of the burner to move between the said tubes andthe said bore; and in which the upper header of the boiler is spaced from the said bore of the water heater, radially of the boiler, by a minor fraction of the aforesaid distance so as to reduce the velocity at which combustion gases move between the upper header and the said bore; and a tubular bafile depending from the'upper header substantially flush with the periphery of that header, the baflle presenting its lower end above the midheight of the vertical spacing between the two headers; and upwardly open drop tubes depending from the bottom of the upper header into the space surrounded by the said riser tubes, the said drop tubes presenting closed lower ends at a common elevation adjacent to but not lower than that of the lower edge of the tubular baflle.

RUDOLF KROGER. 

